I find that when shooting in low light, I am always making the trade off between blurry photos or noisy photos. One thing I have realized, is that if I use a low ISO and underexpose a photo (fast shutter speed) and then ramp up the exposure of the RAW file in post production, it looks roughly the same (in terms of noisiness) as if I take the same photo with the same fast shutter speed and a high ISO. Is there actually any difference?

So is changing the ISO before you take a photo effectively the same as tweaking the exposure after you take a photo?

I ask because I have to go through menus to get to the ISO setting and I frequently forget to change it to what I need. It would be easier if I could just leave it on 100 and then just underexpose shots rather than change the ISO setting

Unless you plan on blowing up your pics to an insane size, changing the ISO from 100 to 200 or 300 is going to have a negligible effect at most. Shoot with a slightly higher ISO and adjust the RAW data afterward.

As long as there isn't any lost data on the low end, you should be able to adjust the exposure in postproduction without much added noise if any (provided you are working with RAW).

ISO in digital cameras refers to how many cells on the CCD correspond to one pixel in the image. The lower the ISO, the lower the number of cells that correspond to a single pixel. The higher the ISO, the higher the number of corresponding cells.

When you tweak in raw, you're doing the exact same thing, but instead of letting the camera's OS do the interpolation for you, you're using your computer. The trick is, if you ask the computer to do that interpolation, you'll get some computational artifacts that would not appear if you had your camera do it for you.

Learn to use camera, not the computer later, your shots will be better. You actually need to think about it when you are shooting there are things like shutter speed and f stop that you can't change on the computer, shot it right in camera. The computer should be like a dark room you develop and tweak a little but you shouldn't have to be fixing shots buy more then a stop.

Learn to use camera, not the computer later, your shots will be better. You actually need to think about it when you are shooting there are things like shutter speed and f stop that you can't change on the computer, shot it right in camera. The computer should be like a dark room you develop and tweak a little but you shouldn't have to be fixing shots buy more then a stop.

I know how to use shutter speed and f stop thanks.

My point was that if I am shooting in low light with high shutter speed (aperture open all the way), I either need to up the ISO or underexpose the photo.

My question was whther these both gave the same result after correcting the exposure in the raw file. The answer I got was yes.

Since fiddling with the ISO requires picking through menus, I am much happier to leave the ISO on 100 and adjust the shutter speed and aperture to achieve the same result.

Learn to use camera, not the computer later, your shots will be better. You actually need to think about it when you are shooting there are things like shutter speed and f stop that you can't change on the computer, shot it right in camera. The computer should be like a dark room you develop and tweak a little but you shouldn't have to be fixing shots buy more then a stop.

I know how to use shutter speed and f stop thanks.

My point was that if I am shooting in low light with high shutter speed (aperture open all the way), I either need to up the ISO or underexpose the photo.

My question was whther these both gave the same result after correcting the exposure in the raw file. The answer I got was yes.

Since fiddling with the ISO requires picking through menus, I am much happier to leave the ISO on 100 and adjust the shutter speed and aperture to achieve the same result.

Actually the results will be very different. Unless you have a shitty camera then upping iso to 800 should not be bad enough to notice at regular sizes. 1600 looks perfectly fine with todays imaging. If you do underexpose and then change exposure in the computer the grain will in every case be way worse. Also colors, contrast and shadow detail will be horrible. The sensor itself changes it sensitivity it does not shoot at one iso and then adjust in camera.

I didn't say you didn't know how, I'm saying if you can fix it in the camera do it. You have to change other things as well. I feel there is also more artifacts when you use the computer. Even though I have been told that they are the same mathematical equation that makes it work.

Learn to use camera, not the computer later, your shots will be better. You actually need to think about it when you are shooting there are things like shutter speed and f stop that you can't change on the computer, shot it right in camera. The computer should be like a dark room you develop and tweak a little but you shouldn't have to be fixing shots buy more then a stop.

I know how to use shutter speed and f stop thanks.

My point was that if I am shooting in low light with high shutter speed (aperture open all the way), I either need to up the ISO or underexpose the photo.

My question was whther these both gave the same result after correcting the exposure in the raw file. The answer I got was yes.

Since fiddling with the ISO requires picking through menus, I am much happier to leave the ISO on 100 and adjust the shutter speed and aperture to achieve the same result.

Actually the results will be very different. Unless you have a shitty camera then upping iso to 800 should not be bad enough to notice at regular sizes. 1600 looks perfectly fine with todays imaging. If you do underexpose and then change exposure in the computer the grain will in every case be way worse. Also colors, contrast and shadow detail will be horrible. The sensor itself changes it sensitivity it does not shoot at one iso and then adjust in camera.

I should clarify, since its my opinion that's leading him astray. Just because the end result is approximately the same, and the computer is trying to emulate what's going on in the camera, doesn't mean that they are precisely equal Digital photo-manipulation leads to artifacting something fierce. These are always very apparent when you look at the end product.

Get your exposures right before doing the rest. You should have a good understanding of the limits of a given ISO setting before you start shooting, just like we had to with film cameras. If you're thinking "I'll just change the ISO for this shot and leave it for the rest", your approach to shooting is ALL WRONG.

Pick your ISO ahead of time with an idea of what the scale of all the shots from your session will be, then adjust lens, aperture, and exposure to fit the range allotted to you by that ISO setting. If you cannot get the grain size/depth of field/exposure time combo that you want, maybe you need to think about different equipment.

I typically use ISO 100 b/w film when I do star photography, mostly because the low sensitivity lets me screw up the exposure by fifteen minutes or so and doesn't ruin the picture. Its a lot more effective than trying to make ISO 800 film do the same job with lots of wasted photo-paper. Even when I pushed the development (that is, set my camera so it would meter for a different ISO, then developed the film so that it was very high contrast), I still kept the same ISO for the entire shoot.

I find that when shooting in low light, I am always making the trade off between blurry photos or noisy photos. One thing I have realized, is that if I use a low ISO and underexpose a photo (fast shutter speed) and then ramp up the exposure of the RAW file in post production, it looks roughly the same (in terms of noisiness) as if I take the same photo with the same fast shutter speed and a high ISO. Is there actually any difference?

So is changing the ISO before you take a photo effectively the same as tweaking the exposure after you take a photo?

I ask because I have to go through menus to get to the ISO setting and I frequently forget to change it to what I need. It would be easier if I could just leave it on 100 and then just underexpose shots rather than change the ISO setting

First off, NO. WHile raising the ISO is merely increasing power to the sensor to gain sensitivity, there is a lot going on in the imaging pipeline that isn't going on in the RAW converter.

For instance, how can say the D200 and D40X have vastly different image quality EVEN IN RAW if both use the same sensor if a lot of processing isn't happening to RAW images. It can't. It's why Pentax, Nikon and Sony all used Sony's 10MP sensor but none had the same RAW IQ.

The D200/K10D/D40X were all CCDs but CMOS is the new fangled wonder sensor because it has some advantages, including on the sensor noise reduction. So the CMOS is doing reduction before it even enters the imaging processor which then puts your camera makers stamp on it.

After extensive testing with both under exposing and pushing the photo in RAW and exposing at a proper ISO all the way right (to the point my highlights DON'T CLIP but almost clip), I've found exposing to the right is ideal. What you describe as your process would be exposing to the left.

I was shooting hockey a few years ago for an AHL team. Canon shooters would always contact me and ask, "how are your shots so clean, everything I heard about Pentax says I have like a 5 stop advantage" (ok I'm joking on the 5 stops, but they would say 2 stops)

Actually it was about 1/3 stop (but even that was offset by the fact that Canon used more NR even on RAW images, leaving less detail for me to work with), viral marketing is awesome but rarely true, and I made up for it by exposing to the right, rather than crossing my fingers and doing the under exposure dance. Because I exposed properly, I actually reversed their 1/3 stop advantage and probably gave myself 1/2 stop and had significantly more detail to work with as well.

Finally, the higher the ISO is, the lower the exposure latitude, so basically at 100 you might be able to play around 3/4 of a stop in post processing, but at 1600 I found that I had no more than 1/3 stop (really 1/4) to get usuable/printable shots. Fortunately my stuff was only getting used for cards, web, and small low color photos.

Here is why...

Noise in most images at high (or low) iso is in the shadows. Therefore, high key scenes like say hockey will not have noise unless you f' up the exposure. So I started bumping my ISO to from 1000 to 1600 and noticed noise was very similar, only because I was no longer pushing the images in Light Room, I was now getting cleaner shadows. So my images actually looked better at 1600 than 1000 or 1250.

Then I noticed it I opened up a bit more or dropped the shutter to the point that the brightest highlights clipped just barely, the rest of the highlights were pushed right (histogram) I was seeing less and less dark mid tone and shadow noise.

So essentially (barely) overexposing at high ISO is really the key to reducing shadow noise, which is generally the only noise you see.

After that I run a selective noise reduction using Nik Dfine, which I target ONLY the shadow colors. Reds, blacks, dark purples. The ice, mid tone skin, white helmets, etc don't get any NR applied.

Finally, not all sensors have linear IQ dropoffs with ISO. An example that comes to mind K10D at ISO 400 takes a big hit vs it's competion, yet at 640 and 800 it actually improves (has better IQ) than the same competition. So don't be so sure that shooting at 1250 will yield better results than shooting at 1600 or 2500.

I'd love for you to post 2 100% crops of images that you underexposed and shot properly, if you are getting equal results, I am buying that software!

This is really bad advice, the RAW converter (Lightroom, etc) has very little latitude vs proper exposure in camera.

I really want to see some results, and notations of the software, perhaps my software is just really old.

This reminds me of a program called FocusMajic, it takes out of focus images and applies a crazy multi stage focus algorithm to essentially get them in focus. However, it's not the same as properly focusing the camera, even though for slightly out of focus images it does work pretty well.

You many understand f stop and shutter speed but do you think about them? I normally shoot on a aperture priority and my camera picks the shutter speed. I don't know how you are shooting, but changing the ISO should change how everything is shoot. The shutter speed and f stop will be different at 100 iso then 1600 iso, you can't just decide to change it later on the computer. I would say if you shoot in the studio on manual mode on a tripod you wouldn't notice a big difference but in real world shooting you will. Don't be lazy, you should look at the lighting for a shoot pic the ISO then work with you f stops and shutter speed to get the image you want. Then in the computer you can then fix small mistakes.

So I read through this whole thread thinking to myself that it is always better to expose properly in the camera than to do it in post processing, but I did understand that it can be a pain to change the ISO if you have to dig through menus to do it.

Finally you gave me the clue that I needed when you said that you are shooting a D60. For your info, on the D60 you can program the timer button to be whatever you want. When I had a D60 I obviously programed this button to be the ISO button, that way I had access to all three fundamental shooting parameters without any menu hunting. Try it out, it works like a charm and that way you can expose properly without digging through any menus.

That really doesn't matter, just cause you had it propped doesn't mean it had the same focus, that could have stopped the camera shake but not necessarily.

I'm not sure what kind of pictures you take that you can not take the 10 secs to change the iso, you don't need to change it for each shot. If you want to be lazy that is your deal, if you forget once in a while this will help you save the images. Yet no one will agree with you to not shoot it right. Do it right its simple and you seem to know what to do just don't be lazy and do it.

That really doesn't matter, just cause you had it propped doesn't mean it had the same focus, that could have stopped the camera shake but not necessarily.

I'm not sure what kind of pictures you take that you can not take the 10 secs to change the iso, you don't need to change it for each shot. If you want to be lazy that is your deal, if you forget once in a while this will help you save the images. Yet no one will agree with you to not shoot it right. Do it right its simple and you seem to know what to do just don't be lazy and do it.

If the camera is on manual focus, and has two shots from the same location of the same subject, how does the focus change?

And why so angry at me? I asked a single straight forward question. I never argued that shooting an underexposed picture will be better. I asked if it would be equivalent to shooting a high ISO picture. I got two different answers and eventually just did the test to find out for myself. I never called anybody stupid, or made crazy claims, but half of the responses are along the lines of "Learn to use a camera newb"

First, look at the purple noise in the midtown areas. do you not see the vertical banding?

Second look at the noise in the background. See the much more prominent blue noise?

Third, the focus is off. Sorry but the left image is soft, not just from noise reduction, from either shake or other movement.

For slow shutter speeds you need either a cable release or IR remote, even touching the shutter introduces shake.

What camera are you shooting? The ISO 1600 was awful to begin with...

BTW, if your camera is to hard to change shutter speeds than you need a new camera. I realize in a digital age we change shutter speeds much more often but you shouldn't need to change shot to shot, if you are than you need a camera with solid external controls.

First, look at the purple noise in the midtown areas. do you not see the vertical banding?

Second look at the noise in the background. See the much more prominent blue noise?

Third, the focus is off. Sorry but the left image is soft, not just from noise reduction, from either shake or other movement.

For slow shutter speeds you need either a cable release or IR remote, even touching the shutter introduces shake.

What camera are you shooting? The ISO 1600 was awful to begin with...

BTW, if your camera is to hard to change shutter speeds than you need a new camera. I realize in a digital age we change shutter speeds much more often but you shouldn't need to change shot to shot, if you are than you need a camera with solid external controls.

Now I am confused. Are you talking shutter speed or ISO? I am usually changing shutter speed on every shot. The camera is hard to change ISO on, but I don't have $$ to shell out on a higher level DSLR. I will try the suggestion of reprogramming the timer button.

That really doesn't matter, just cause you had it propped doesn't mean it had the same focus, that could have stopped the camera shake but not necessarily.

I'm not sure what kind of pictures you take that you can not take the 10 secs to change the iso, you don't need to change it for each shot. If you want to be lazy that is your deal, if you forget once in a while this will help you save the images. Yet no one will agree with you to not shoot it right. Do it right its simple and you seem to know what to do just don't be lazy and do it.

If the camera is on manual focus, and has two shots from the same location of the same subject, how does the focus change?

And why so angry at me? I asked a single straight forward question. I never argued that shooting an underexposed picture will be better. I asked if it would be equivalent to shooting a high ISO picture. I got two different answers and eventually just did the test to find out for myself. I never called anybody stupid, or made crazy claims, but half of the responses are along the lines of "Learn to use a camera newb"

Why so angry, most people that will comment on this post are passionate about photography, and it just sounds like you are being lazy. Imagine if you just said will a two piece anchor be as good as a three piece I don't like to take the time to do it right. Every one would say your going to die noob. Now cutting this corner wont result in death or injury (unless you are shooting a wedding and mess up)

Asking if it is all right to cut the corner just makes you look lazy and like you don't know what you are doing. You don't need our approval do what every you want. I will be shooting right in my camera cause I care about my images

That really doesn't matter, just cause you had it propped doesn't mean it had the same focus, that could have stopped the camera shake but not necessarily.

I'm not sure what kind of pictures you take that you can not take the 10 secs to change the iso, you don't need to change it for each shot. If you want to be lazy that is your deal, if you forget once in a while this will help you save the images. Yet no one will agree with you to not shoot it right. Do it right its simple and you seem to know what to do just don't be lazy and do it.

If the camera is on manual focus, and has two shots from the same location of the same subject, how does the focus change?

And why so angry at me? I asked a single straight forward question. I never argued that shooting an underexposed picture will be better. I asked if it would be equivalent to shooting a high ISO picture. I got two different answers and eventually just did the test to find out for myself. I never called anybody stupid, or made crazy claims, but half of the responses are along the lines of "Learn to use a camera newb"

Why so angry, most people that will comment on this post are passionate about photography, and it just sounds like you are being lazy. Imagine if you just said will a two piece anchor be as good as a three piece I don't like to take the time to do it right. Every one would say your going to die noob. Now cutting this corner wont result in death or injury (unless you are shooting a wedding and mess up)

Asking if it is all right to cut the corner just makes you look lazy and like you don't know what you are doing. You don't need our approval do what every you want. I will be shooting right in my camera cause I care about my images

I think many would say that it depends. Having all of the knowledge is what will let you make the right choice. In some situations going fast is safer than maximizing safety at every belay. Sometimes two anchors is good enough, like almost every bolted anchor. Sometimes it is important to know what the trade offs are between choices, instead of just saying, this is the right way, only do it this way.

If I know what the trade off is between high ISO and underexposure, I can judge for myself whether it is worthwhile to hunt through a menu, and maybe miss a shot or end up with a slightly grainy shot. Not all photos are destined for art galleries.

That really doesn't matter, just cause you had it propped doesn't mean it had the same focus, that could have stopped the camera shake but not necessarily.

I'm not sure what kind of pictures you take that you can not take the 10 secs to change the iso, you don't need to change it for each shot. If you want to be lazy that is your deal, if you forget once in a while this will help you save the images. Yet no one will agree with you to not shoot it right. Do it right its simple and you seem to know what to do just don't be lazy and do it.

If the camera is on manual focus, and has two shots from the same location of the same subject, how does the focus change?

And why so angry at me? I asked a single straight forward question. I never argued that shooting an underexposed picture will be better. I asked if it would be equivalent to shooting a high ISO picture. I got two different answers and eventually just did the test to find out for myself. I never called anybody stupid, or made crazy claims, but half of the responses are along the lines of "Learn to use a camera newb"

Why so angry, most people that will comment on this post are passionate about photography, and it just sounds like you are being lazy. Imagine if you just said will a two piece anchor be as good as a three piece I don't like to take the time to do it right. Every one would say your going to die noob. Now cutting this corner wont result in death or injury (unless you are shooting a wedding and mess up)

Asking if it is all right to cut the corner just makes you look lazy and like you don't know what you are doing. You don't need our approval do what every you want. I will be shooting right in my camera cause I care about my images

I think many would say that it depends. Having all of the knowledge is what will let you make the right choice. In some situations going fast is safer than maximizing safety at every belay. Sometimes two anchors is good enough, like almost every bolted anchor. Sometimes it is important to know what the trade offs are between choices, instead of just saying, this is the right way, only do it this way.

If I know what the trade off is between high ISO and underexposure, I can judge for myself whether it is worthwhile to hunt through a menu, and maybe miss a shot or end up with a slightly grainy shot. Not all photos are destined for art galleries.

Hey, if putting your name on garbage is what you want to do, I'm not gonna waste my time arguing with you.

If you change ISO that frequently it's time to man up and buy a real camera. Changing ISO shouldn't involve more than a few button presses totaling 2-3 seconds.

This is why I feel like while there are MANY good digital only photographers, people that started with film, or decided to learn how to shoot film recently are significantly better at the fundamentals of photographic technique.

In the old days you put a roll of 100 ISO in and you lived with it, unless you did a mid roll rewind or had a second camera with faster film. you figured out how to make it work.

If you really use ISO that much as a variable to exposure, you should get a camera with an auto ISO mode, at the very least.